In the title compound, {[Cu(C(10)H(14)N(4))(2)(H(2)O)(2)](NO(3))(2)}(n), the Cu(II) ion lies on an inversion center and is six-coordinated in an octa-hedral environment by four N atoms from four different 1,1'-butane-1,4-diyldiimidazole ligands and two O atoms from the two water mol-ecules. Bridging by the ligands results in a ribbon structure. Adjacent ribbons are linked to the nitrate anions via O-H⋯O hydrogen bonds, forming layers. One nitrate O atom is disordered equally over two positions.